|Most ISPs don't require any special settings in Windows to connect to the internet.|
You can only connect to one ISP at a time, and you can only connect to the internet wirelessly or via a wired connection at one time, not both ways, from the same computer.
If you have only one computer at your location....
The simplest way of doing what you want to do is to have a modem or combo router / modem for each ISP, and disconnect the modem or combo router/modem network connection to your computer for one ISP and use the the one for the internet connection you want to use.
E.g. if one uses a cable modem or combo router/ modem, the other a DSL modem or combo router / modem, if you connect to them via a network cable, unplug the cable from your computer to the ISPs device you don't want to use, or disable one connection in Windows Network settings if you have two wired network adapters on your computer, and use the other one you want to use.
If you're connecting to a wireless router or wireless combo router / modem wirelessly, you can only use one wireless connection at a time from a single wireless network adapter on your computer in any case - you could select the connection to the ISPs router or combo router / modem you want to use in your wireless settings, just like you can connect to other such devices that in other locations that are close enough to where your computer is outside where you are located.
If you have more than one computer in your location, and if you are the only one who uses one of them, you could connect to the router or combo router / modem you want to use for your ISP, and the other people could be connected to the same for the other ISP .
(If you have a standalone router, it needs to be connected to a stand alone high speed modem, probably by means of a network cable between them. It's recommended you use a standalone router, or a combo router / modem, between you and the internet because the router has a built in "hardware" firewall that protects you a lot better than if you are connecting to a standalone modem directly. )